The Big O's roof will be replaced (at a cost of up to $300M)

The Quebec government has given the green light to replace the roof of the Olympic stadium.

There have been thousands of rips in the fabric roof over the years and it must be replaced if the stadium is to be used.

The Olympic Installation Board will now begin a two-year process of deciding what materials the roof will be made from -- but officials said it will be soft and will be a fixed structure. The stadium design cannot support a metal retractable roof, they said.

The budget for the third roof on the stadium will between $200 and $300 million and the OIB would like it to be installed by 2023.

Avi Friedman, PhD in Architecture and a professor at McGill University, said designing a roof for a stadium has been demonstrated to be difficult.

"I don't think that Montrealers will be able to, willing to stomach another large sum of money and increase. And again mistakes in this type of construction and in this type of project may end up in spending many more millions," said Friedman.

The current roof is a fibreglass and Teflon shell supported by a steel frame that sits on the stadium, and cables strung from the tower.

It is nearly 20 years old and has been riddled with problems since the beginning, including in 1999 when the roof tore and snow and ice crashed through onto the Montreal Auto Show.

Since, then the number of rips has gone from 30 to 40 a year to more than 1,200 annually, making the stadium only useable in warmer months.

The roof has ripped 7,453 times over the past ten years, according to a Radio-Canada report.

The original fabric roof was retractable, but also ripped multiple times. It was retracted and installed fewer than 100 times before being removed.

“It was meant to be a very advanced stadium but unfortunately because of the many things that happened over time, it became something that we are not very proud of,” said Friedman.

Montreal's Olympic Stadium with its retractable roof was designed by architect Roger Taillibert and it was built for the 1976 summer games, although the first roof was only installed in 1987.

Though some critics have suggested demolishing the building, Olympic Stadium CEO Michel Labrecque said that's not an option.

“I think it will be a shame to demolish something that our parents, father and grandfather built, that is unique, that is an architectural symbol of Montreal and Quebec,” he said, adding that he doesn’t believe it’s cost effective. “To say, okay, we'll start from scratch, it will cost $500 to $700 million. It will take five years, will be truly complicated, 7,500 trucks will be needed it's a no way.”

On Thursday, Premier Philippe Couillard defended the decision to spend more public dollars on the stadium, saying it can't continue to be used if the roof isn't repaired and abandoning the Big O isn't an option.

Its use is limited, said Labrecque.

“The best time of the year for exhibitions, for shows, is between October and March and the stadium is under a protocol. If it snows more than three centimetres we have to close everything here,” he said, adding that the new roof will double the amount of time the stadium can be used.

“What we want here is a roof that is foolproof 365 days of the year,” he said.